This invention relates to polyblends and specifically to polyblends of polyvinyl chloride (PVC) with certain polymers capable of conferring on the PVC improved resistance to elevated temperatures.
PVC is a widely used polymer with many advantages. It has good molding characteristics especially where plasticized, it has excellent clarity, physical properties and UV stability and it is inherently resistant to bruising. It is however comparatively sensitive to elevated temperatures such that it cannot be used in applications in which it is necessary that the product retain its dimensional stability at temperatures above about 65.degree.-70.degree. C.
The present invention provides a means of improving the dimensional stability of PVC without significant deterioration in critical physical properties. This is achieved by blending certain compatible styrenic polymers with the PVC.